More than $25 billion was paid in 1988 to networks and stations for the broadcasting of television commercials and programs. During the past several years, the number of stations, cable systems and cable channels have greatly increased, thereby increasing the total number of hours that programs and commercials are transmitted for television reception. For 1989, it is estimated that more than 300,000,000 programs and commercial messages will be broadcast in the United States. In view of the multibillion dollar investment that purchasing of broadcast time involves, it is extremely important to accurately monitor each and every broadcast that is paid for. Often, a program or commercial is not broadcast at the time that was contracted and paid for. There is an increasing need, therefore, for a system that can monitor programs and commercials and accurately and efficiently determine the occurrence of the broadcast, as well as the exact length, source, date, and time thereof and the quality of the monitored signal.
Various prior art systems have been developed over the years in an attempt to fulfill the above-described need. However, all of these prior art systems suffer from serious drawbacks, and do not perform with sufficient reliability or accuracy. U.S. Pat. Nos. 3,919,479; 4,025,851; 4,230,990; 4,613,904; 4,639,779; and 4,739,398 are examples of such prior art systems. Typically, videotapes for which broadcast time is purchased, are syndicated television shows or are independent stand alone commercials. The syndicated programs typically have television commercials which are combined with and integrated into the syndicated program tape. Independent stand alone commercials are separate tapes which are broadcast independently from the television program.
The most basic method of monitoring is, essentially, a manual method which is dependent upon individuals monitoring and logging desired information about each broadcast. This prior art manual method suffers from the obvious drawbacks of being unreliable and very expensive because it depends upon the accuracy and attention span of the large number of individuals who monitor each broadcast.
Another prior art system employs pattern recognition in analyzing the video signals. This method attempts to match the pattern produced by a program, or portions thereof, to the pattern of various programs or commercials stored in memory. The matching of the program pattern to the pattern stored in memory occurs as a result of a search of a very large sized database consisting of an extremely large number of individual samples. This system has many drawbacks, however, such as, for example, the requirement of the extremely large database and unreliability due to signal distortion and the fact that only partial samples are obtained for matching.
Another prior art method for monitoring broadcasts employs an active and unique code for each program and/or commercial. The code is placed into the scan-line of the vertical blanking interval (scan-lines 14 through 21 of both fields 1 and 2 or odd and even). There is, however, no standardized way in which broadcast or television station video signal processing equipment treats the vertical blanking interval. Very often, identification codes placed in the vertical blanking interval of program material to be aired are stripped out of the video signal by the processing equipment during tape duplication or station broadcast. Further, this method generally relies on a code which is not continuously variant along the length of the videotape. This makes it difficult, if not impossible, to accurately determine whether the broadcast had complete audio and video components, the length of the signal and the arrangement of the airing order of the monitored material.
Another prior system employs an identifying code on scan-line 22 of the video signal. This method does not, however, decode the signal continuously and contiguously, throughout the entire broadcast desired to be detected, and, instead, is detected only in random fashion across the entire length of the program, (generally a short commercial), thereby preventing the accurate determination of whether the program or commercial ran for its full length, or which parts, if any, of the television program material were missing from the transmission or just missing from detection.
Typically, the prior art systems, that employ some form of encoding, monitor the signal by scanning from channel to channel, as opposed to continuously monitoring each channel without interruption. This prior art scanning method permits loss of data due to breaks in the observing process. The accuracy of this prior art scanning method is also proportional to the number of stations being scanned, thereby resulting in a loss of accuracy and reliability. Gaps in the continuity of the program material or a momentary loss of audio or video signal, are thereby repeatedly permitted to go undetected. Additionally, scanning requires the identifying data of the encoded signal to be compressed into a portion of the video format. This compression requires a very fast data rate in order to compensate for the breaks in the observing process. The compression of the identifying data of the encoded signal is highly vulnerable to noise, such as noise arising from multipathing of the broadcast signal, and thereby is often and easily distorted. This distortion creates further inaccuracies and lack of reliability in the monitoring process. Further, none of these systems monitor, at a desirable level of accuracy and reliability, the quality (i.e. in visual and audio components) of the monitored signal. Moreover, the encoding methods of these prior art systems often lead to inaccurate decoding, and thus monitoring, due to failure to perceive the coded scan line, either correctly for each frame, or nowhere near continuously for each frame.
Another problem which the prior art fails to address is the situation encountered when encoding and decoding syndicated television programs. Although such programs have television commercials integrated into a continuous tape in addition to the syndicated television program material, such tapes also have blank spots which roughly correspond to the duration of independent stand alone commercials. These time slots appear on the tape of the syndicated television program as black portions or "time away" portions. During the time away portion of a syndicated television program tape, during broadcast, an independent stand alone commercial, television station promo or other type of stand alone tape, is broadcast from another video tape player. The length of time of the independent broadcast does not necessarily coincide with the length of the time away portion of the syndicated television program tape. Under the prior art systems, since they do not number or do not otherwise individually and uniquely identify each and every frame, it is extremely difficult, if not impossible, to determine the amount of time away. Adding to the problem is the fact that the time away does not necessarily correspond to the length of time that independent stand alone video material has been broadcast.
None of these prior art systems continuously and contiguously encode and number or otherwise individually and uniquely identify every frame of a video signal desired to be detected. None of these systems continuously monitor, without interruptions due to scanning, a broadcast frequency or channel of interest. In view of these drawbacks as well as others, all of these prior art methods suffer from an undesirable recovery rate of the signal being monitored and a resulting lack of accuracy and/or completeness in monitoring.